Automatic drain for steam-engine cylinders



(No Model.)

C. A. DUNHAM. AUTOMATIC DRAIN FOR STEAM ENGINE GYLINDERS. No. 583,037. Patented May 25,1897.

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UNITED STATES PATENT OFFICE.

CLAYTON A. DUNHAM, OF OLARINDA, IOW5A.

AUTOIVIATIIC DRAIN FOR STEAM-ENGINE CYLINDERS.

SPECIFICATION forming part of Letters Patent No. 583,037, dated May 25, 1897.

Application filed J' une 1 7, 1 S 9 6.

To @ZZ whom, t may concern:

Be it known that I, CLAYTON AUBRA DUN- HAM, of Clarinda, in the county of Page and State of Iowa, have nventeda new and Improved Automatic Drain for Steam-Engine Cylinders, of which the following is a full, clear, and exact description.

The object of the invention is to provide a new and improved automatic drain for relieving steam-engine cylinders of all water of condensation without permitting an undesirable escape ofthe steam and preventing the breaking of the cylinder-heads by accumulated water or priming of the boiler.

The invention consists principally of a pipe connected at its ends with the ends of the steam-cylinder, a piston-valve connected with the pipe,and a drain-cup into which discharges the said valve, the drain-cup being provided with an expansion-plu g normally open for the escape of water of condensation and adapted to close by the action 01": the steam.

The invention also consists of certain parts and details and combinations of the same, as will be fully described hereinafter and then pointed out in the claims.

Reference is to kbe had to the accompanying drawings, forming a part of this specification, in which similar characters of reference indicate corresponding parts in all the views.

Figure l is a side elevation of the improvement. Fig. 2 is a transverse section of the same on the line 2 2 of Fig. l, and Fig. 3 is a sectional side elevation of the valve on the line 3 3 of Fig. 2.

The improved drain is provided with a pipe A, made approximately U shape and connected at its ends with the ends of the cylininder. In the pipe A is interposed the casing B' of the valve B, discharging into a globevalve C, supporting at its bottom a drain-cup D and provided with a discharge-pipe E, as indicated in Fig. 2. The valve B is provided with two hollow stems B2 and B3, tted to slide in corresponding bores in the casing B', the said stems being formed with ports a and b for connecting either end of the pipe A with the outlet of the valve-casing.

At the adjacent ends of the stems B2 and B5 is held a disk-valve having two faces B4 and B5, adapted to be seatedon valve-seats B5 and Serial No. 595,861. (No model.)

B7, respectively, formed in the casing B and leading to bores B8 and B9, respectively, surrounding the stems B2 and B3.

The outlet B10 of the casingB extends downwardly and receives the upper end of the valve-body C of the globe-valve C, the said valve-body being provided with two oppositely-arran ged valve-seats C2 and C3, adapted to be engaged by the double-faced disk-valve C4, held on the stem G5, screwing in the casing C and provided on its outer end with a hand-wheel C6 for turning the stem C5 to move the disk-valve C4 onto either of the seats C2 or C5. The seat C2 leads to the discharge-pipe E, and the seat is normally closed by the diskvalve C4. The other seat C3 leads to the discharge end G7 of the casing of the body C', and this end C7 is connected with the hollow shank D of the drain-cup.

On the shank Dl is formed the cup D2, and the bore of the shank is connected by a series of channels D5 with the interior of the cup, as plainly indicated in Fig. 2. On the lower edge of the cup D2is formed a seat D4, adapted to be engaged by a plug D5, made of vulcanized rubber or other suitable material, which expands when subjected to heat. The plug D5 is held on a stem D6, depending from the bottom of the cup and at the center thereof, and the base oi' the plug rests on a metallic plate D7, supported by a nut D8, screwing on the lower end of the stem D5. The nut D8 is made of an easily-breakable material, such as brittle metal, to permit the plug D5 and the plate D7 to slide olf the stem D"y and seat D4 of the cup D2 whenever the plug is subjected to an excessive pressure.

The operation of the device is as follows: When the piston in the cylinder is at one end thereof and the steam passes between the piston and the cylinder-head to force the piston forward, then the water of condensation at this end of the cylinder readilypasses through the corresponding end of the pipe A to the valve B," and the pressure of the steam ac ting on the corresponding valve-stein B2 or B5 forces the same to the other side until the corresponding valve-face B5 or B4 is seated on the corresponding seatB7 or B5. The ports a and b permit the water of condensation to run into the outlet B10, from which the water can pass through the valve C into the eupD and through the opening between the plug D and the seat Dl to the outside, it being understood that the said plug D5 normally forms a space with the seat for the escape of the water. As the piston moves to the end of its stroke the cylinder is thoroughly drained, and when the exhaust closes then` the com pression-space is on the opposite side of the piston, and pressure is exerted on the pistonvalve to force the same in the opposite direction and connect this end of the cylinder with the atmosphere by way 01".' the valve C and cup D. Now the steam colning into either end of the cylinder produces the water of condensation by the steam coming in contact .with the cold surface of the cylinder, and

LII

this water of condensation is drained by the pipe A, the valve B, and the cup D, as above explained. Thus the simple change of the position of the piston-valve provides an outlet for the water of condensation from each end of the cylinder, it being understood that when one end of the cylinder is drained the other end of the cylinder connected with the pipe is closed to the atmosphere by way of the pipe A. After a few strokes of the piston in the cylinder there is practically dry steam only in the cylinder, and this steam, by passing through the pipe A in the same manner as the water of condensation, finally reaches the cup D and heats the expansionplug D5. The latter now expands and in doing so seats itself on the seat D4, thus closing the cup D and preventing the escape of the steam. Should an overabundance of water be drawn into the cylinder at one time, then the momentum of the piston creates a greater pressure of the water on the compression end than the pressure of steam on the opposite end, and in this case thc pistonvalvc is forced against the pressure of the steam and consequently the drain-cup D is flooded, and by the excessive pressure the nut Ds is burst to permit the plug D5 and plate DT to leave the cup D, so that the water can escape without any harm being donc to the engine or any of its parts. The handwhcel CG is then turned so as to move the disk-valve C4 from the seat C2 and onto the seat C3 to permit the water and steam to escape from the globe-valve through the discharge-pipe E. The expansion-plug D5 and plate D7 are again placed in position in the cup D2 and secured thereto by a nut DS. It will be seen that by the arrangement described complete protection is given to the cylinder and at the same time the pressure in the cylinder is not lost or in any way interfered with.

It is further understood that the device gives immediate escape for an excessive amount of water, should it enter the cylinder from any cause besides mere condensation.

The drain is applicable to all classes of reciprocating engines, vertical or horizontal, compound or triple-expansion, condensing or non-condensing. The drain will be of great service on elevator-pumps and electric-light engines, or may be readily applied to marine or locomotive engines.

It is expressly understood that in the drain described the steam side of the cylinder has vent to the atmosphere, and consequently cushion is saved, and it matters not how large an amount of water or how great a pressure in the cylinder, as the drain is always open to that side of the cylinder that has the most pressure. Should the pressure on the exhaust side rise above that on the steam side, then the valve shifts, as above described, to the opposite seat, thereby forming a direct outlet or escape.

Having thus described my invention, I claim as new and desire to secure by Letters Patentl. An automatic drain for steam-engine cylinders, comprising a pipe adapted to be connected at its ends with the ends of the steam-cylinder, a piston-valve connected with the said pipe, and a drain-cup into which discharges the said valve, the drain-cup being provided with an expansiblc plug normally open for the escape of water of condensation and adapted to close when subjected to heat, substantially as shown and described.

2. An automatic drain for steam-engine cylinders, comprising a pipe adapted to be connected at its ends with the ends of the steam-cylinder, a piston-valve connected with the said pipe, a drain-cup into which discharges the said valve, the drain-cup being provided with an expansible plug normally open for the escape of water of condensation and adapted to close when subjected to heat, and a globe-valve interposed between the said piston-valve and the said drain-cup, the said globe-valvehavinga discharge-pipe, substantially as shown and described.

3. An automatic drain for steam-engine cylinders, provided with a piston-valve, comprising a casing adapted to connect at its ends with the ends of the cylinder, a two-faced disk-valve, hollow stems extending in opposite directions from the said valve, each stem having ports, and the stems being iitted to slide in the ends of the said casing, the port-s being adapted to connect thc ends of the casing with the discharge end of the casing, substantially as shown and described.

l. A drip-cup having an inlet-oriee and an open side, a stem extending through the drip-cup, a plate carried by one end of the stem and adjacent to the open side, a yielding nut for holding the plate on the stem, the nut giving way to excessive pressure within the cup, and a plug sustained bythe plate and capable of expanding when subjected to heat, substantially as described.

5. A drip-cup having an inlet-orifice and having an open side, a plate held normally over said open side, yielding means by which the plate is held in place, such means giving way to excessive pressure within the drip- ICO IIL)

cup, and a plug held within the drip-cup and expanding to close the saine upon the application of heat, substantially as described.

6. A drip-cup having an inlet-orifice and an opening in one side, an expansive tapering plug, the large portion of Which is situated outward from the small end and Within the opening in the cup, the plug expanding against the Walls of said opening to close the cup, and means for yieldingly holding the plug in place such means giving Way to excessive pressure in the cup whereby the plug When expanded may be blown from the cup, substantially as described.

7. A drip-cup having an inlet-orifice and an opening in one side, and an expansive tapering plug, the large portion of which is outward from the small end and situate Within the CLAYTON A. DUNHAM.

XVitnesses:

L. 0. STEBBINs, K. C. BEAN. 

